VEGFA and osteosarcoma: The rate of necrosis in resected tumor specimens, of more or less than 90% in respectively "good" or "poor" responders to neoadjuvant chemotherapy [3] still remains the more important prognostic factor [1]; however, if chemotherapy can affect tumor angiogenesis, different expression levels of VEGF in osteosarcoma before and after chemotherapy could be considered an additional biologic factor predictive of potential distant metastasis and/or local relapse and a marker of chemosensitivity.